1. Technical Field
The present invention relates to a door opening and closing device that enables a door to be closed tightly and to be widely opened.
2. Background Arts
Generally, a door opening and closing device is adopted in various apparatuses and machines, and used for opening and closing a door formed on a main body of a certain apparatus (machine).
A Patent Document 1 (Japanese Patent Application Publication No. 2009-14969) discloses an image forming apparatus provided with such a door opening and closing device. In the image forming apparatus, an opening used for clearing a paper jam or replacing a service part is opened and closed by a door, and the door is opened and closed by the door opening and closing device.
External auxiliary devices can be connected with the image forming apparatus. Specifically, a large-capacity paper feeder as the auxiliary device can be connected with a right side panel of the image forming apparatus, and a post-processing device as the auxiliary device is connected with a left side panel of the image forming apparatus. An opening for clearing a paper jam or replacing a service part is formed on each of the side panels, and the opening is opened and closed by a door.
When a user has to clear a paper jam or replace a service part, it is necessary to open the door in order to access the opening after moving the large-capacity paper feeder or the post-processing device. If the door is supported by well-known hinges and swingably opened and closed, a space required for opening and closing the door becomes large. Therefore, the door(s) on the side panel (s) disclosed in the Patent Document 1 is laterally slid to a front side of the image forming apparatus. Guide members in a pair are provided parallel to each other along upper and lower edges of the opening.
According to the door opening and closing device disclosed in the patent Document 1, a distance required for inevitably moving the auxiliary device(s) of the image forming apparatus can be shortened when clearing a paper jam or replacing a service part, compared with an apparatus provided with a hinge-type door. In addition, a space to be secured around the apparatus can be saved. Further, operability for clearing a paper jam or replacing a service part can be improved.
A Patent Document 2 (Japanese Patent Application Publication No. 2003-209373) discloses another door opening and closing device adopted in an electrical instrument. The door opening and closing device includes a pair of protrusions that serve as hinge pins and are coaxially protruded outward in an opposite direction from a door. The hinge pins are inserted into reception holes. End surfaces of the hinge pins and bottom surfaces of the reception holes are formed as inclined surfaces that are inclined with respect to an axis of the hinge pins.
According to the door opening and closing device disclosed in the patent Document 2, the inclined surface of the hinge pin and the inclined surface of the insertion hole are parallel when the door is closed. These two inclined surfaces are twisted about the axis when the door is opened, and thereby they function as a dumper.